Sharif Digital Repository

Dijet production has been measured in pPb collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV. A data sample corresponding to an integrated luminosity of 35 nb−1 was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle correlations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters (E4<|η|<5.2 T). For pPb collisions, the dijet transverse momentum ratio and the width of the distribution of dijet azimuthal angle difference are comparable to the same quantities obtained from a simulated pp reference and insensitive to E4<|η|<5.2 T. In... 

The reaction of a solution of MoO2(acac)2 in CH3OH and salicylidene 2-picoloyl hydrazone as a tridentate ONO donor Schiff base (ONO) afford a six-coordinated Mo(VI) complex [MoO2(ONO)(CH3OH)], with a distorted octahedral configuration. [MoO2(ONO)(CH3OH)] was isolated as an air-stable crystalline solid and fully characterized by single-crystal X-ray structure analysis. [MoO2(ONO)(CH3OH)] shows reactivity in the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide as the oxidant at room temperature under air  

Vendor-managed inventory (VMI) is a popular policy in supply chain management (SCM) to decrease bullwhip effect. Since the transportation cost plays an important role in VMI and because the demands are often fuzzy, this paper develops a VMI model in a multi-retailer single-vendor SCM under the consignment stock policy. The aim is to find optimal retailers' order quantities so that the total inventory and transportation cost are minimized while several constraints are satisfied. Because of the NP-hardness of the problem, an algorithm based on particle swarm optimization (PSO) is proposed to find a near optimum solution, where the centroid defuzzification method is employed for... 

GAC has been modified by loading of potassium nickel hexacyanoferrate (KNiCF) as a new adsorbent for cesium adsorption. The potassium nickel hexacyanoferrate-loaded granular activated carbon (KNiCF-GAC) was characterized using powder x-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm data, infrared spectroscopy, and its cesium adsorption performance in aqueous solution was investigated. The effect of the various parameters such as initial pH value of the solution, contact time, temperature, and initial concentration of the cesium ion on the adsorption efficiencies of KNiCF-GAC have been studied systematically by batch experiments. The adsorption isotherm of KNiCF-GAC was... 

In order to simulate the performance of pure methane in chemical looping using iron-based oxygen carrier, simultaneously production of three pure streams of hydrogen, nitrogen and carbon dioxide has been investigated. For this purpose, proper operating conditions have been discussed for maximum production of hydrogen, complete consumption of oxygen of inlet air and complete combustion of methane. Professional software is used to simulate the chemical looping reactors and optimize their output streams. Results show that in this process each mole of methane fuel can produce 2.533, 2.65 and 0.99 mol of pure N 2, H2 and CO2, respectively which contributes 80.2% energy conversion of CH4 to H2.... 

The brushless doubly fed induction generator (BDFIG) has substantial benefits, which make it an attractive alternative as a wind generator. However, it suffers from lower efficiency and larger dimensions in comparison with the doubly fed induction generator. A major part of drawbacks arises from undesirable spatial harmonics of air-gap magnetic field. Calculation of core loss is an important issue in optimal design studies to improve the performance characteristics. The iron loss is higher and has a more complex nature in BDFIGs in contrast with conventional machines. Furthermore, additional losses cannot be ignored due to a high level of spatial harmonics distortion. This paper aims to... 

A search for excited quarks decaying into the γ + jet final state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7 fb-1 collected by the CMS experiment in proton-proton collisions at √s=8TeV at the LHC. Events with photons and jets with high transverse momenta are selected and the γ + jet invariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; masses below 3.5 TeV are excluded at 95% confidence... 

In this paper, the path independent interaction integral has been implemented in the framework of the extended finite element method for mixed mode adiabatic cracks under thermo-mechanical loadings particularly in orthotropic non-homogenous materials. The mesh insensitivity and increased accuracy due to the thermal and displacement asymptotic analytical solutions are discussed and the contour independency of the interaction integral is investigated in different examples. Finally, the problem of crack propagation in orthotropic FGM materials under the thermal loading is investigated to assess the accuracy and robustness of proposed approach  

In this letter, we study the Gaussian two-way relay channel (GTWRC) with a direct link in which two nodes want to exchange information with each other with the help of a relay node in the presence of a direct link between two nodes. Specially, we focus on a protocol with four phases, which is called the hybrid broadcast (HBC) protocol. In the HBC protocol, sequential transmissions from both users are followed by a transmission from the relay. Using nested lattice codes, we obtain a new achievable rate region for this protocol. In fact, utilizing a four-stage lattice partition chain, we introduce an intermediate lattice in our lattice-based coding scheme, and by using it, we split the... 

Permutation approach is suggested as a method to investigate financial time series in micro scales. The method is used to see how high frequency trading in recent years has affected the micro patterns which may be seen in financial time series. Tick to tick exchange rates are considered as examples. It is seen that variety of patterns evolve through time; and that the scale over which the target markets have no dominant patterns, have decreased steadily over time with the emergence of higher frequency trading  

We present a Vector Dark Matter (VDM) model that explains the 3.5 keV line recently observed in the XMM-Newton observatory data from galaxy clusters. In this model, dark matter is composed of two vector bosons, V and V', which couple to the photon through an effective generalized Chern-Simons coupling, gV. V' is slightly heavier than V with a mass splitting mV' - mV 3.5 keV. The decay of V' to V and a photon gives rise to the 3.5 keV line. The production of V and V' takes place in the early universe within the freeze-in framework through the effective gV coupling when mV' < T < Λ, Λ being the cut-off above which the effective gV coupling is not valid. We introduce a high energy model that... 

The photon orbital and/or spin angular-momentum absorption in absorbing plasma medium causes the circular motion of electrons and generate the azimuthal component of current density. The axial magnetic field generation due to the azimuthal component of generated current density is known as inverse Faraday effect. In this paper, the axial magnetic field generation in an absorbing plasma with ramped density by the propagation of linear polarized Laguerre-Gaussian beam is taken into consideration. It is shown that the positive slope of the initial electron density causes a considerable enhancement of self-generated axial magnetic field. The magnetic field enhancement depends on the twisted... 

Numerical simulation of the electrical field distribution helps in-depth understanding of the mechanisms behind the responses and the benefits of the high voltage pulse comminution. The COMSOL Multiphysics package was used to numerically simulate the effect of ore compositions in this study. Regarding phosphate ore particles shape and composition, the effects of mineral composition, particle size, particle shape and electrodes distance were investigated on the electrical field intensity and distribution. The results show that the induced electrical field is significantly dependent on the electrical properties of minerals, the feed particle size and the location of conductive minerals in... 

The evolution of microstructure and the mechanical properties of an aluminum 6061 alloy tube subjected to a novel severe plastic deformation process called tube channel pressing were studied. Results show that the tube channel pressing causes an impressive grain refinement and strengthening of the material. As an illustration, mostly ultrafine grained tube (D-=760nm) bearing the yield strength of 352. MPa can be obtained after 5 passes of tube channel pressing. Additionally, the tube channel pressing causes the heterogeneous grain refinement resulting in a bimodal distribution of size of grains after 7th pass. Therefore, it can be inferred that the main microstructure refining mechanism... 

In this study, mathematical modeling of fixed-bed plasma reactor operated under isothermal condition was investigated. In this process, methane and acetylene were the inputted feed and ethane, ethylene, propylene, propane, i-butane, and n-butane were the output products. The amount of methane conversion obtained was 12.7% for the former feed, however, if pure methane was inputted this conversion rose to 13.8%. Furthermore, the plasma process enhanced the conversion as well as the selectivity toward the desired product and yield. In the present study, when methane and acetylene were fed at a molar ratio of CH4/C2H2 = 10 to the reactor, the selectivity of C2, C3, and C4 hydrocarbons was... 

This paper surveys methods to aggregate redundant crowd labels in order to estimate unknown true labels. It presents a unified statistical latent model where the differences among popular methods in the field correspond to different choices for the parameters of the model. Afterward, algorithms to make inference on these models will be surveyed. Moreover, adaptive methods which iteratively collect labels based on the previously collected labels and estimated models will be discussed. In addition, this paper compares the distinguished methods and provides guidelines for future work required to address the current open issues.Recently, there has been a burst in the number of research projects... 

Modern power systems have been faced with a rising appeal for the upgrade to a highly intelligent generation of electricity networks known as the smart grid. Thus, security for the smart grid has emerged as an important issue. Recently, Hur proposed an attribute based data sharing for smart grid which unfortunately is vulnerable to the denial of service (DoS) attack. Moreover, it does not support the user revocation property and the grid system manager cannot prevent the revoked user of having access to the shared data in the storage center. For these weaknesses, we suggest an efficient revocable data sharing scheme which is immune against DoS attack. In addition, we present the security... 

Co-deposition of RF-sputtering and RF-PECVD from acetylene gas and Au target were used to prepare sensor chip of gold nanoparticles (Au NPs). Deposition conditions were optimized to reach a Localized Surface Plasmon Resonance (LSPR) sensor chip of Au NPs with particle size less than 10 nm. The RF power was set at 180 W and the initial gas pressure was set at 0.035 mbar. Transmission Electron Microscopy (TEM) images and Atomic Force Microscopy (AFM) data were used to investigate particles size and surface morphology of LSPR sensor chip. The Au and C content of the LSPR sensor chip of Au NPs was obtained from X-ray photoelectron spectroscopy (XPS). The hydrogenated amorphous carbon (a-C:H)... 

In this work, asphaltene adsorption in a sandstone core sample under dynamic conditions and during miscible CO2 injection was studied using live oil sample which is close to real conditions in petroleum reservoirs. In order to investigate of damage in sandstone core sample by the deposited material such as asphaltene, the morphology analysis of sandstone core sample using scanning electron microscopic method was studied. Also analyses of the adsorbed material in sandstone core sample by Soxhlet extraction using an azeotrope mixture and with SARA method were performed. The experimental results show that by increasing the flow rate of injected CO2, the amount of asphaltene in retained material... 

The authors present the results of numerical tests and simulations to investigate and analyze the likelihood of asphaltene precipitation and deposition during CO2 flooding in a reservoir. The effects of asphaltene precipitation on oil properties such as oil viscosity and density during miscible CO2 flooding process were elaborated by using Winprop software of Computer Modeling Group. Also oil properties change during CO 2 miscible flooding by numerical slim tube were investigated by a compositional simulator (GEM). A fluid sample of Saskatchewan Reservoir that had been flooded miscibly with CO2 was chosen for performing the sensitivity analyses. The results showed that asphaltene...